Automatic means for the movement of comminuted materials



1, 1953 J. R. STEPHENSON ,648 4-6 AUTOMATIC MEANS FOR THE MOVEMENT 0F'COMMINUTED MATERIALS Filed April 5, 1948 2 Sheets-Sheet J.

Aug. 11, 1953 J. R. STEPHENSON AUTOMATIC MEANS FOR THE MOVEMENT OFCOMMINUTED MATERIALS Filed April 5, 1948 2 Sheets-Sheet 2 FIG3 D2vemfor: mes R. Gfep/l/QSO/JZ.

Patented Aug. 11, 1953 AUTOMATIC MEANS FOR THE MOVEMENT OF COMMINUTEDMATERIALS James R. Stephenson, Winnipeg, Manitoba,

Canad Application April 5, 1948, Serial No. 18,898

4 Claims.

My invention relates to new and useful improvements in feedingmechanisms for furnace stokers, the principal object of the inventionbeing to provide a device of the character herewithin described wherebyan adequate supply of fuel is available at all times at the stokerfeeding auger.

A further object of the invention is to provide a device of thecharacter herewithin described which due to its construction willoperate :over a substantial area of the fuel bin, thus reducing thenecessity for supervision of the stoker and the manual handling of thefuel.

Another object of my invention is to provide a device of the characterherewithin described which operates when there is a deficiency of fuelat the feeding auger and which ceases to operatejwhen this deficiencyhas been remedied.

A still further object of my invention is to provide a device of thecharacter herewithin described whereby the possibility of the actuatingswitch becoming inoperative due to interference of the fuel iseliminated.

Another object of my invention is to provide a device of the characterherewithin described which is designed for use in a bin or hopper havinga horizontal floor, thereby resulting in the utilization of the entirefuel storage space.

A further object of my invention is to provide a device of the characterherewithin described which incorporates a fire-proof switch in order toactuate a remote source of power, thus eliminating the danger ofexplosion taking place within the fuel bin.

Another object of my invention is to provide a device of the characterherewithin described which is of sturdy construction and which isreadily adaptable for use in the movement of other comminuted materialsuch as crushed rock, grain, or the like.

With the foregoing objects in view, and such other objects andadvantages as will become apparent to those skilled in the art to whichthis invention relates as this specification proceeds, my inventionconsists essentially in the arrangement and construction of parts all ashereinafter more particularly described, reference being had to theaccompanying drawings, in which:

Figure 1 is a perspective reperesentation of my device installed for usein a fuel bin.

Figure 2 is an enlarged fragmentary view along the lines 22 of Figure l.

Figure 3 is an enlarged fragmentary perspective view of my switchassembly and discharge cavity.

In the drawings like characters of reference indicate correspondingparts in the different figures.

Since the inception of the self-feeding stoker system for furnacesconsiderable difficulty has been experienced in providing a device whichis readily adaptable to comparatively large installations where it isnot possible, for economic or structural reasons, to use theconventional sloping floor hopper. Conversion of relatively largecapacity furnaces situated in confined locations has been delayedbecause of the difficulty in providing adequate space for theinstallation of special hoppers, and considerable difficulty has alsobeen experienced in attempting to provide a device controlled by themain furnace stoker mechanism which will maintain a constant andadequate supply of fuel at the point of discharge without unduepulverization of the coal.

Many diverse systems have been designed in the past in an endeavour toovercome these disadvantages but the majority have failed due to thelack of an efficient switch mechanism specifically intended to beoperated by the movement of comminuted material. Consequently I haveinvented the device hereinafter to be described in order to overcome theforegoing objection, and which incorporates a novel switch particularlysuited for use with any comminuted material.

Proceeding now to describe my invention in detail it will be seen uponreference to the accompanying drawings to consist of the vertical driveshaft I mounted for rotation within the barrel 2 which in turn issupported by the pedestal bearing 3 attached to the superstructure 4 bythe bolts 5 or similar means. In order to prevent the possibility of anygas or dust becoming ignited by electrical arcing the motive unit 6 issituated exteriorly of the fuel bin and power is transmitted by thebelts l connectingthe pulleys 8 and 9 which of course are splined orkeyed to their respective shafts. The lowermost end of the verticalshaft l enters the gear box l0 and actuates the sweeping auger ilthrough the medium of conventional worm and pinion gearings. The gearbox is rigidly attached to the aforementioned barrel 2 by means offlange l2 and becomes part of the sweeping assembly collectivelydesignated I3 pivoting therewith as will hereinafter be explained.

It will be seen that the sweeping assembly is horizontally disposed,parallel with and adjacent to the floor of the bin and comprises theaforementioned sweeping auger li supported by the bearing I4 attached tothe gear box It and by the bearing I5 which is carried by the end plateI6 of the elongated fender IT. The fender which in this embodiment isconstructed from angle iron comprises the raking portion [8 which issubstantially in contact with the floor of the bin, and the horizontallyelongated substantially vertically disposed plate l9 which as well asacting as a stiffening web for the assembly also prevents undesirabledisplacement of fuel by the sweeping auger II as will hereinafter bedescribed.

The diagonal stiffening rod is rigidly connected to the outboard end 2|of the fender and extends upwardly and inwardly to connect via thesleeve 2| with the aforementioned vertical barrel 2 substantiallytowards the uppermost end thereof. This bracing rod provides rigidity tothe structure and maintains the sweeping assembly substantially incontact with the floor of the bin whilst allowing the complete assemblyto move in a horizontal plane pivoting in the aforementioned pedestalbearings 3. Attached sub- 'stantially towards the outboard end of theaforementioned fender I8 is the rope or cable 22 extending over theconveniently located pulleys 23 to the adjustable weight 24 which servesthe purpose of maintaining the sweeping assembly [3 in contact with themargin of the fuel mass at all times. It will be realized that theweight and pulley system may be replaced or assisted by hydraulic,pneumatic, or other mechanical means, but the arrangement illustrated isconsidered adequate for this embodiment.

The angulated finger 25 is rigidly attached on the outboard end of thesweeping auger II and rotates therewith in order to provide clearancefor the end plate IS with the fuel mass, as it will be realized that theweight 24 may be insufficient to overcome the inertia of the sweepingassembly if the end plate is registering against a relatively largepiece of fuel. The auger ll may be provided with either a left orrighthanded flight, but it is desired that the lefthanded flight shownin this embodiment be utilized as it has been found advantageous to havethe overside of the auger rotating towards the aforementioned elongatedfender I! as this assists in the movement of the fuel towards thedischarge cavity 26 with the minimum of pulverization. It will .beappreciated however that whether a left or right-handed flight isutilized the rotation of the auger should be such that the material isurged towards the discharge cavity and in the appended claims for thepurpose of explication the auger flight has been defined as movingtowards the point of discharge.

The rotation of the auger H is controlled by the switch operatingmovement collectively designated 2! which is rigidly attached to thegear box by the bracket 28 in a position superjacent to the dischargecavity 26 and in advance of the longitudinal axis of the auger. Themovement comprises the horizontally disposed rod 29 mounted for rotationwithin the offstanding angulated bracket 30 and having a plurality ofspaced and parallel flexible wire fingers 3| depending therefrom. Thewire fingers are shown in this embodiment rigidly inserted within a headpiece 3 l which is adjustably mounted upon the rod 39 by the clips 32,thus forming what I designate as a material interceptable component 32.Rigidly attached to the inboard end of the aforementioned rod 29 andextending transversely therefrom is the switch actuating actuating bar33.

bar 33 which connects via the linkage 34 to the switch 35. The switchmakes and breaks the circuit controlling the operation of theaforementioned motive unit 6 and is shown in the on" position in Figures1 and 2 of the accompanying drawings. From the foregoing it will beappreciated that the material intercepting component 32 will normallymaintain the switch in this position assisted by the weight 36 attachedto the outboard end of the aforementioned switch A relatively smallextension spring ma be substituted for the weight spanning the outboardend of the actuatin bar and the lower portion of the gear box I0. It isdesirable that this switch should be of fireproof construction in orderto eliminate the possibility of explosion taking place within the bin orhopper.

Having described my invention in detail, its method of operation willnow be presented.

When the fuel is loaded into the bin or' hopper the sweep arm assembly[3 should be moved in the direction of the arrow3l sufficient to ensurethat all the fuel is deposited in advance of the unit. If the quantityof fuel supplied is too great to permit the angle of repose of the fuelto reach the floor, the fuel will feed by gravity to the dischargecavity 26 until the fuel adjacent the cavity is evacuated, thereupon thedevice will operate as hereinafter described, although withouttransverse movement of the sweeping assembly. The assembly is kept incontact with the margin of the mass of fuel by the weight 24, andgradually sweeps across the floor as the fuel is consumed. When adeficiency of fuel occurs in the discharge reservoir 26 the resilientwire'fingers'3l will take up a vertical position assisted by the offsetweight 36 thus operating the switch which completes the circuit throughthe medium 'of electrical conduit 38 thereby starting the rotor 6. Thiscauses rota tion of the auger I l in a clockwise direction when viewedfrom the outboard'end l of the'asse-m'bly as hereinbefore described,thereby causing fuel to move towards the discharge reservoir 26. Thefuel is maintained within the auger channel by means of the relativelyhigh vertical fender l1 and when the reservoir becomes full, the fuelcommences to build up between the inboard end of the auger H and theaforementioned resilient wire fingers 3|. This excess fuel causesthe'displacement of the Wire fingers away from the auger as clearlyshown in Figure 3 of the accom panying drawings, and-it is desired thatthe resiliency of the fingers should be such that the inertia of theweight 36 will not be overcome until several of the fingers aredistorted. It will be appreciated that if the displacement of a singlefinger only was relied upon to overcome this inertia, then prematureactuation of the switch unit might result due to the interference of arelatively large piece of fuel. When sufficient fuel has been deliveredto the discharge reservoir to cause the displacement of several of thewire fingers, the inertia of the weight 36 is overcome, thus allowingpartial rotation of the rod 29 in the direction of the arrow 39 therebyactuating the switch 35 via the aforementioned linkage 34v and breakingthe circuit of the motive unit 6. The main stoker feed auger 40, whichis situatedsu b stantially towards the bottom of the discharge reservoir26, conveys the fuel therefrom to the furnace (not illustrated), thequantity being regulated thermostatically in the conventionalmajn ner.When the level of fuel in the discharge'reservoir commences to fall, thematerial intercept ing component returns to its normally verticalposition assisted by the weight 36, thus closing the circuit andstarting the motive unit 6. The weight 24 ensures continuous contact ofthe sweeping assembly with the margin of the fuel mass, thereby assuringthe complete evacuation of the fuel from the bin without the need forsupervision or manual handling of the fuel.

Since various modifications can be made in my invention as hereinabovedescribed, and many apparently widely different embodiments of same madewithin the spirit and scope of the accompanying claims without departingfrom such spirit and scope, it is intended that all matter contained inthe accompanyin specification shall be interpreted as illustrative onlyand not in a limiting sense.

What I claim as my invention is:

1. In the evacuation of comminuted materials from bins or hoppers, meansfor urging the comminuted mass to the point of discharge comprising asweeping assembly including a horizontally disposed sweep-arm assemblymovable in a horizontal plane substantially parallel to and in proximityto the bin or hopper floor, said sweeping assembly being pivoted forsaid movement substantially above the point of discharge, a source ofpower for efiecting such movement, said assembly embodying an elongatedconveyor, an elongated fender in proximate parallel and trailingrelation thereto, said fender including a horizontally elongated,substantially vertically disposed plate, means for urging said sweep armassembly against the margin of said mass, a switch for initiatingactuation of said conveyor, and a switch actuator adjacent said point ofdischarge consisting of a rotatable rod, a material interceptablecomponent secured to said rod and projecting downwardly therefrom withthe distal end of said component slightly spaced from and in advance ofsaid elongated conveyor, and a switch throwing element extending betweensaid rod and said switch and actuable by said rod upon movement of saidcomponent by comminuted material.

2. In the evacuation of comminuted materials from bins or hoppers, meansfor urging the comminuted mass to the point of discharge comprising asweeping assembly including a horizontally disposed sweep-arm assemblymovable substantially parallel to and in proximity to the bin or hopperfloor, said sweeping assembly being pivoted for-said movementsubstantially above the point of discharge, a source of power forefiecting such movement, said assembly embodying an elongated conveyor,an elongated fender in proximate parallel and trailing relation thereto,said fender including a horizontally elongated, substantially verticallydisposed plate, means for urging said sweep arm assembly against themargin of said mass, a switch for initiating actuation of said conveyor,and a switch actuator adjacent said point of discharge, consisting of arotatable rod, a material interceptable component in the form of a setof flexible fingers secured to and projecting downwardly from said rodwith the distal ends of said fingers parallel with. and slightly spacedfrom and in advance of said elont5 gated conveyor, and a switch throwingelement extending between said rod and said switch and actuable by saidrod upon movement of said fingers by comminuted material.

3. In the evacuation of comminuted materials from bins or hoppers, meansfor urging the comminuted mass to the point of discharge comprising asweeping assembly including a horizontally disposed sweep-arm assemblymovable substantially parallel to and in proximity to the bin or hopperfloor, said sweeping assembly being pivoted for said movementsubstantially above the point of discharge, a source of power foreflecting such movement, said assembly embodying an elongated conveyor,an elongated fender in proximate parallel and trailing relation thereto,said fender including a horizontally elongated, substantially verticallydisposed plate, means for urging said sweep arm assembly against themargin of said mass, a switch for initiating actuation of said conveyor,and a switch actuator adjacent said point of discharge movable out ofswitch operating position by the movement of said comminuted material,and a radially extending rotatable finger on the end of said elongatedconveyor opposite to the point of discharge.

4. In the evacuation of comminuted materials from bins or hoppers, meansfor urging the comminuted mass to the point of discharge comprising asweeping assembly including a horizontally disposed sweep-arm assemblymovable substantially parallel to and in proximity to the bin or hopperfloor, said sweeping assembly being pivoted for said movementsubstantially above the point of discharge, a source of power foreffecting such movement, said assembly embodying an elongated conveyor,an elongated fender in proximate parallel and trailing relation thereto,said fender including a horizontally elongated, substantially verticallydisposed plate, means for urging said sweep arm assembly against themargin of said mass, a switch for initiating actuation of said conveyor,and a switch actuator adjacent said point of discharge, consisting of arotatable rod, a material interceptable component in the form of a setof flexible fingers secured to and projecting downwardly therefrom withthe distal ends of said fingers parallel with and slightly spaced fromand in advance of said elongated conveyor, and a switch throwing elementextending between said rod and said switch and actuable by said rod uponmovement of said component by comminuted material, and a radiallyextending rotatable finger on the end of said elongated conveyoropposite to the point of discharge.

JAMES R. STEPHENSON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,479,990 Keys Jan. 8, 1924 1,482,524 Robinson Feb. 5, 19241,570,085 Saxe Jan. 19, 1926 2,232,545 Lum Feb. 18, 1941 2,445,056Cordis July 13, 1948

